These calls were by the bird when was approached slowly by me when it was approached at the pond edge (G. F. Budney - 6May2015). The first calls were on the ground and then it few toward Steve who was recording it.
NOTES: [These vocalizations appear to represent the "Alarm-attack" Calls described by Oring (1968. Wilson Bull. 80:395-420; Figure 5C) given by a bird during migration. There is a small possibility that these are instead "Contact" calls, but I do not believe that this is the case given the wide frequency-range of the notes. Quality added (1-2) - CAM - 23 February 2005]